About Converged and Hyper Converged Infrastructure

Month: August 2016

I have struggled to understand the concepts of VMware NSX major functionality like NSX Edge Services Gateway, Edge Distributed Logical Router and their options, hence I am writing this series to explain in detail what I have learnt in the past few days regarding these functions in layman terms and not the marketing jargon I see on the internet regarding VMware NSX.

Part 1 — NSX Edge Services Gateway

It is very easy to create Logical switches in the NSX option using vCenter server web client

The hard part comes when you have multiple networks (with subnets) you want to activate on the edge services gateway so that they communicate to each other and to the external uplink on the edge services gateway.

Here is how I did it,

First, I created two Logical switches

App-LG

Web-LG

I have an L2 physical network switch for my home lab, so I am sure I can’t do L3 routing, in this instance I am going to show you how to create an Edge Services gateway with the proper interfaces to have multiple subnets communicating between them on a VM connected to one of these logical switches.

First, we deploy an Edge services gateway using the default options and the interfaces as shown below:

Here are the interfaces which I have configured on the gateway

In the above picture, I created one vNIC as an Uplink (I named it as External) and the IP address I gave that interface as 192.168.0.79/24 (192.168.0.0/24) is my LAN subnet in my home

Then I created two Internal interfaces (I named one as Internal) with interface IP addresses as 172.168.10.2/24 and 172.168.11.2/24 where the IP addresses 172.168.10.2 and 172.168.11.2 act as IP default gateways to the VMs attached to logical gateways App-LG and Web-LG which are connected to the two internal interfaces

Also, I configured the Default gateway in the Edge Services Gateway configuration while deploying as shown:

Now, that we have configured the L2 logical networks on the Edge Services Gateway with the interfaces, let us go to the VMs and see how the communication goes on through the logical networks

We have a test VM called Win7 connected to App-LG (which has an interface IP address as 172.168.10.2) hence the default gateway of this VM will be 172.168.10.2

Here we see the communication using ping to all the interfaces ip addresses both internal and external

In the above picture, you can see that we are able to ping the three interfaces (192.168.0.79, 172.168.10.2 and 172.168.11.2) even though the VM gateway is 172.168.10.2 since its logical gateway is App-LG.

Also, note that we weren’t able to ping my default gateway 192.168.0.1 since there is no interface or routing to 192.168.0.1 in the edge services gateway. We will cover this under routing and NSX Distributed Logical Router part next.

By this, I am concluding this part as I wanted to show you how logical networks can be used with VMS and how their networks can route between the different subnets using Edge services gateway. This is for the East-West traffic between VMS.

As of 8/18/2016 Nutanix (as far as I know), Nutanix started selling its platform (Acropolis Hypervisor and Prism Software) on Cisco UCS C-series servers. Nutanix now supports the following UCS servers —

C220-M4S

C240-M4L

C240-M4SX

Looks like the Nutanix Software bundle comes in Acropolis Pro and Ultimate Editions.

To harden your ESXi 6.0 hosts, we disable the MOB service so that any attacker can’t get to the web browser and access the MOB of the ESXi host (ex: https://esxi01.lab.com/mob), this setting will disable one of the attack vectors of theESXi hosts in the environment.

to do this, you SSH into the ESXi host where you want to disable the mob service and perform the following commands

esxi01# vim-cmd proxysvc/remove_service "/mob" "httpsWithRedirect"

to verify if the mob service has been removed from the ESXi host, use the following command

esxi01# vim-cmd proxysvc/service_list

the above command will list all the services on the ESXi host, look for the service “/mob”, if you don’t see this service, then it has been removed. if it is still there, then you will have to perform the first command and reboot the ESXi host to disable the mob service from the host.

Recently, I had to shutdown multiple ports on a Cisco MDS 9396 switch for maintenance. I had to look up the commands to do it as I haven’t done it yet as most of the customers will either shut down the switch completely or just shutdown the required ports and not multiple ports on the switch.

here are the commands to shutdown all ports on the switch at once:

MDS1# conf t

MDS1(config)# int fc1/1-40

MDS1(config-if)#shutdown

If you have to shutdown the ports and they are not in sequence, here is the command

Recently, I was working on an UCS blade firmware upgrade along with esxi upgrade from esxi 5.5 to 6.0 and came across this error where the esxi host became unresponsive with an error “can’t fork” on its DCUI.

here is a little background on this story, this particular blade was B240 blade which was being used as SAP HANA blade by the customer and the firmware upgrade and esxi upgrade went fine and two days later the host became unresponsive and we couldn’t connect to it using SSH, DCUI, etc, connecting to the kvm console revealed the below screen when we went to its Alt+F1 command interface

we had to bounce the box and we had to reduce the linux vm memory which was hosting SAP HANA on it to be 10% less than the memory of the esxi host.

Conclusion: The HANA VM (linux) on the esxi host should have 10% less memory than the overall memory of the esxi host to avoid this problem.

Recently, I had to install the Cisco vem module onto an esxi 6 host as it was not installed and i couldn’t join the esxi host to the cisco nexus 1000v distributed switch. here is the process on how to first check if the vem module is installed on the esxi host.

SSH into the esxi host and run the following commands to check if the VEM module is installed

host# esxcli software vib list | grep -i vem

the above command will display the cisco vem module installed on the esxi host, if nothing is displayed then you will have to install the vem module by downloading the vem vib from the nexus 1kv in the environment.

i did it by going to https://nexus1kv_hostname in a web browser which will display you the vibs which you can download from nexus 1000v, download the vem vib associated with your environment and run the following command to install the vib onto the esxi host

Recently I had to restart the web-client service in vcsa 6.0 U1 appliance and found out that the web client service is called differently than in the windows vCenter. the web client service in the vcsa is called vSphere-client

here are the commands to start, stop and restart any services in the vcsa appliance.

To restart a vCenter Server and/or Platform Services Controller service using the command-line:
Log in as root through an SSH or console session on the vCenter Server Appliance.
Run this command to enable the shell: